以氨基酸为连接子的吉西他滨-聚谷氨酸偶合物设计、合成及评价

目的设计、合成抗肿瘤药物吉西他滨与聚谷氨酸的偶合物,通过调节连接子的结构以控制药物的释放,提高抗肿瘤药物的疗效。方法首先合成吉西他滨3′-或5′-的氨基酸酯衍生物,然后在DCC作用下,氨基酸的氨基与聚谷氨酸分子中的羧基缩合,得到以氨基酸为连接子的吉西他滨-聚谷氨酸偶合物;用紫外法测定偶合物载药量;用HPLC法测定偶合物在水溶液或血浆中的稳定性。结果与结论共合成目标化合物11个,载药量为25%~30%。稳定性试验结果表明,偶合物在水溶性或血浆中能够稳定地释放游离药物,氨基酸类型及连接位置可影响药物的释放速率,偶合物PG-Ala-3′-Gem的释放速率最快,4h释放50%的药物,而PG-Val-3′-Gem和PG-Ala-5′-Gem在48h分别释放30.3%和43.5%;偶合物在血浆中的释放速率略快于水溶液中的释放速率。     

pH敏感聚(2-乙基-2-噁唑啉)-壳聚糖-阿霉素共聚物胶束的制备及性质考察

目的合成pH敏感两亲性接枝共聚物聚(2-乙基-2-噁唑啉)-壳聚糖-阿霉素(PEOz-g-CS-HyzDOX),采用透析法制备阿霉素pH敏感两亲性共聚物胶束并对其相关的制剂学性质、细胞抑制及细胞摄取行为进行考察。方法分别利用透射电镜(TEM)、动态光散射法(DLS)和zeta电位分析仪对胶束的形态、粒径和表面电位进行表征;采用透析法考察载药聚合物胶束的体外释放行为;采用MTT法考察聚合物胶束的细胞抑制作用。结果反应产物使用红外及核磁表征,确定为目标产物;PEOz-g-CS-Hyz-DOX聚合物胶束载药量为4.2%。采用透析法制备的载阿霉素聚(2-乙基-2-噁唑啉)-壳聚糖丁二酸单甲酯胶束(PEOz-g-CSMS/DOX)载药量可达5.62%,包封率为59.35%;两种胶束的粒径均较小且粒径分布很窄,胶束粒子为类球形且分散良好;两种胶束释药行为体现pH敏感性;PEOz-g-CS-Hyz-DOX聚合物胶束体外细胞毒作用及细胞摄取均优于PEOz-g-CSMS/DOX胶束和阿霉素溶液。结论以壳聚糖为载体的化学腙键释药胶束作为抗肿瘤药物的药物传递系统具有可行性及良好的应用前景。     

壳寡糖-水杨酸接枝物纳米粒用于释放阿霉素的研究

目的 考察壳寡糖/水杨酸纳米粒负载碱化阿霉素的可能性,评价制备而得的微粒给药系统理化性质及其体外释放行为。方法 以碳二亚胺为交联偶合剂合成壳寡糖/水杨酸接枝共聚物,三硝基苯磺酸法测定水杨酸接枝率。运用超声分散法制备壳寡糖/水杨酸空白纳米粒,芘荧光法测定纳米粒临界聚集浓度,动态光散射法测定微粒粒径和表面电位,MTT法考察空白纳米粒的细胞毒性。以碱化阿霉素为模型药物,透析法制备壳寡糖/水杨酸载药纳米粒,经透射电镜考察载药纳米粒的形态,对其体外释放行为进行了研究。结果 合成得到的壳寡糖分子量=9000/水杨酸理论投料量=50%的实际接枝率为16.92%,空白纳米粒的临界聚集浓度为867.0 μg/mL,空白纳米粒的粒径和表面Zeta电位分别为434.0 nm和48.6 mV,对人肝癌细胞Hep-G2的半数抑制浓度为1745μg/mL。在碱化阿霉素理论投药量为10%时壳寡糖/水杨酸载药纳米粒的实际载药量为8.52%,包封率为93.15%。;载药纳米粒的粒径和表面电位分别为214.2 nm和33.6 mV。体外释放结果表明药物的释放呈现pH敏感性;并主要以溶蚀的方式从载体内部释放出来。结论 壳寡糖/水杨酸接枝物可以有效包裹碱化阿霉素并成为粒径均一的纳米粒给药系统。载药纳米粒具有pH敏感和缓释作用。壳寡糖/水杨酸接枝物有望成为潜在的难溶性药物的载体材料。     

正电化修饰的HPMA聚合物-阿霉素接合物的制备表征及对肿瘤细胞摄取的影响

目的:制备2种正电化修饰的N-(2-羟丙基)甲基丙烯酰胺(HPMA)聚合物-阿霉素接合物并表征,分别考察2种接合物的正电基团含量对肿瘤细胞摄取的影响。方法:制备侧链带伯胺基的HPMA聚合物-阿霉素接合物(pHPMA-DOX-APMA)和侧链带胍基的HPMA聚合物-阿霉素接合物(pHPMA-DOX-GPMA),对其药剂学性质如正电基团含量,载药量,Zeta电位和分子量进行表征,进一步考察不同正电基团含量的接合物对MCF-7细胞摄取和毒性的影响。结果:通过自由基聚合反应,2种接合物成功合成。其中pHPMA-DOX-APMA伯胺基含量为0.44~1.57 mmol·g^-1,载药量为7.15%~9.25%;pHPMA-DOX-GPMA胍基含量为0.11~0.54 mmol·g^-1,载药量为7.55%~9.07%;相对分子质量分别为33~38 kDa和32~37 kDa。通过BCA法和MTT法研究分别发现在pHPMA-DOX-APMA中的伯胺基团含量为1.570 mmol·g^-1及pHPMA-DOX-GPMA中的胍基含量为0.260 mmol·g^-1时,肿瘤细胞对阿霉素的摄取量显著增加,二者的IC₅₀与pHPMA-DOX相比显著降低(P<0.05)。结论:成功制备了2种正电化修饰的HPMA聚合物-阿霉素接合物;适当的正电化修饰对阿霉素的肿瘤细胞摄取有促进作用。     

阿霉素聚乳酸微球的制备及体外释药特性研究

目的:对阿霉素聚乳酸微球的制备工艺、含量测定及体外释药特性进行初步研究.方法:以人工合成可生物降解聚合物聚乳酸为载体,采用乳化-溶剂挥发法制备阿霉素聚乳酸微球,用UV-260紫外分光光度计测定其药物含量和体外释药量.结果:所制备的阿霉素聚乳酸微球外形圆整,算术平均球径为55.2 μm,载药量为30.21 μg*mg-1,12 h体外累积释药量36%.结论:聚乳酸微球具有很好的控释能力,使用前景广阔.     

阿霉素共聚物胶束的制备及体外性质研究

目的制备阿霉素共聚物胶束并研究其体外性质。方法采用开环聚合法合成聚乙二醇单甲醚-聚乳酸羟基乙酸（mPEG—PLGA）嵌段共聚物;用透析法、溶剂蒸发法制备空白及载阿霉素胶束;动态光散射仪（DLS）测定其粒径分布;采用紫外分光光度法测定胶束的包封率和载药量。通过体外释药实验研究了载阿霉素胶束的释药特性。结果采用透析法制备载阿霉素胶束大小均匀,平均粒径为（91．1±15．8）nm;药物胶束的包封率为85．2％,载药量为10．4％;与市售阿霉素注射剂相比,载阿霉素胶束具有良好的缓释性能。结论共聚物胶束可作为疏水性药物阿霉素的载体。     

紫杉醇普朗尼克稳定化胶束的制备

目的:制备载紫杉醇的普朗尼克(Pluronic)稳定化胶束。方法:采用插入交联的方法,以普朗尼克P123为材料插入交联剂聚氰基丙烯酸正丁酯制备紫杉醇稳定化胶束。并对其理化性质如粒径,载药量,体外释放度等进行了测定。同时测定了该胶束对HepG-2肝癌细胞的细胞毒性。结果:所制备的载药胶束,多倍冲稀后仍能稳定存在。细胞毒性实验结果表明,稳定胶束对HepG-2肝癌细胞的细胞毒性显著高于原料药。结论:所制备的载紫杉醇胶束性质稳定,细胞毒性增加。     

脑用表阿霉素壳聚糖微球的制备及其特性考察

目的：以壳聚糖为载体材料，表阿霉素为模型药物，制备脑内局部给药缓释微球。方法：以液体石蜡为油相，L-抗坏血酸棕榈酸酯为交联剂，司盘-80为乳化剂，采用乳化化学交联技术制备表阿霉素脑用微球。用动态透析法研究微球的体外释放特性。结果：盐酸表阿霉素/壳聚糖的质量比为1：9的载药微球形态良好，粒径分布较为均匀，平均粒径为（9．3±2．6）μm、载药量为（8．01±0．23）％、包封率为（72．9±2．2）％。体外释放具有良好的缓释效果。结论：所优化的制备工艺稳定，适用于脑用表阿霉素壳聚糖微球的制备。     

表阿霉素免疫纳米微粒的制备及体外抗肿瘤作用研究

目的制备表阿霉素免疫纳米微粒,观察其抗体活性、体外释药及体外抗肿瘤作用。方法利用聚电解质复合法合成载表阿霉素纳米微粒（E-ADM-NPs）,化学交联法合成载表阿霉素的抗血管内皮生长因子受体2（VEGFR2）单克隆抗体纳米微粒。ELISA法检测表阿霉素单克隆抗体纳米微粒（E-ADM-Ab-NPs）的抗体活性,紫外分光光度计测定其体外释药量,MTT法检测其对人肝癌细胞的体外杀伤效应。结果 E-ADM-Ab-NPs的平均粒径为（190±21）nm,抗体活性保存良好;体外释药试验表明,E-ADM-Ab-NPs具有缓释特性,10d累积释药量可达93.46%;E-ADM的体外杀伤效应在1～6d呈时间依赖性,而E-ADM-Ab-NPs则在1～10d均呈时间依赖性,6d时两者的杀伤效应均呈剂量依赖性,且两者间差异无统计学意义（P〉0.05）。结论 E-ADM-Ab-NPs具有药物缓释效应和免疫活性,可延长表阿霉素（E-ADM）对人肝癌细胞的有效作用时间,且并未影响E-ADM的生物学活性。     

贝伐单抗介导的阿霉素白蛋白纳米粒的制备与优化

目的采用Box-Behnken效应面法优化贝伐单抗介导的阿霉素白蛋白纳米粒制备工艺。方法在采用去溶剂化-固化交联法制备出的阿霉素白蛋白纳米粒的基础上,用异型双功能交联剂NHS-PEG3500-MAL作为偶联剂,将贝伐单抗偶联到载药白蛋白纳米粒表面。以2-亚氨基硫烷盐酸盐用量、载药白蛋白纳米粒与贝伐单抗质量比、NHS-PEG3500-MAL用量为影响因素,以纳米粒粒径、载药量和包封率作为评价指标,用三因素三水平的Box-Be-hnken效应面法设计试验,并对免疫纳米粒的制备进行优化;考察制备出的免疫纳米粒的抗体活性保存率及稳定性。结果优化后的处方是2-亚氨基硫烷盐酸盐50μg、DOX-A-NPs与Bevacizumab质量比为27.5 mg.mg-1、NHS-PEG3500-MAL用量为8.8 mg,以此处方制得的免疫纳米粒粒径为(216.1±2.31)nm、载药量为(28.93±0.94)%、包封率为(80.39±2.83)%,测得值与预测值相差较小。结论采用Box-Behnken效应面法优化并制备阿霉素白蛋白免疫纳米粒是可行的。     

Curcumin-derivative nanomicelles for the treatment of triple negative breast cancer

Abstract

Background: Triple negative breast cancer (TNBC) is a subtype of breast cancer characterized by its poor outcome and a lack of targeted therapies. Recently, our laboratory has developed a second generation curcumin derivative, 3,5-bis(3,4,5-trimethoxybenzylidene)-1-methylpiperidine-4-one (RL71) that shows potent in vitro cytotoxicity. RL71 is hydrophobic with poor bioavailability which limits its clinical development.

Purpose: We have designed styrene-co-maleic acid (SMA) micelles encapsulating 5, 10 or 15% RL71 by weight/weight ratio to improve its solubility and pharmacokinetic profile.

Methods: The micelles charge, size and release rate were characterized. We evaluated their cytotoxicity against TNBC cell lines. The internalization of the drug inside the cells was measured by HPLC and the efficiency of the micelles was tested using a tumor spheroid model.

Results: The micelles exhibited mean diameters of 125–185?nm and had a neutral charge. SMA-RL71 micelles have a cytotoxicity profile comparable to the free drug against several TNBC cell lines. Moreover, the 15% loaded micelles increased the stability of RL71 and demonstrated higher activity in a tumor spheroid model.

Conclusion: The current study demonstrates the efficiency of SMA for drug delivery, the influence of physicochemical characteristics on cytotoxicity, and provides the basis for preclinical testing in vivo.     

抗IV型胶原酶单抗与平阳霉素新型免疫偶联物的抗肿瘤作用

目的考察抗IV型胶原酶单抗3G11与平阳霉素(PYM)偶联物的抗肿瘤作用。方法采用多聚谷氨酸(PLG)为中间载体制备3G11-PLG-PYM偶联物,MTT法测定其对肿瘤细胞增殖的抑制作用,以小鼠移植性肝癌H22为模型观察体内抗肿瘤作用。结果偶联物保留了单抗3G11对IV型胶原酶的免疫活性,对体外培养H22和KB细胞的杀伤作用弱于PYM。动物实验中PYM 10 mg·kg^-1对H22肝癌的抑制率为60.6%,而等细胞毒性剂量的3G11-PLG-PYM偶联物抑瘤率达到90.8%,与PYM相比可显著延长小鼠的中位生存时间。结论3G11-PLG-PYM偶联物对小鼠肝癌H22的抑瘤作用比PYM强,可能成为新型的抗肿瘤靶向药物。     

CD44‐Targeted Docetaxel Conjugate for Cancer Cells and Cancer Stem‐Like Cells: A Novel Hyaluronic Acid‐Based Drug Delivery System

A CD44‐targeted macromolecular conjugate of docetaxel was prepared via a pH‐sensitive linkage to hyaluronic acid and was characterized using NMR, gel permeation chromatography, and differential scanning calorimetry. The conjugated species were further evaluated in terms of drug release, cytotoxicity, cellular uptake, cell cycle inhibition, and subacute toxicity in mice. Cellular microscopic studies revealed that CD44‐expressing cells including MCF‐7 cancer stem cells and MDA‐MB‐231 metastatic breast cancer cells had internalized the conjugates via a selective receptor‐mediated mechanism, leading to cell cycle arrest in the G2/M phase. Hyaluronic acid–docetaxel conjugates showed specific toxicity only in CD44‐expressing cells in vitro, along with a decreased risk of neutropenia and dose‐dependent mortality in vivo. Hyaluronic acid–drug conjugates represent a promising and efficient platform for solubilization of sparingly soluble molecules as well as active and selective targeted delivery to cancer cells and cancer stem cells.     

烯二炔类抗肿瘤抗生素单克隆抗体导向药物研究进展

单克隆抗体对相应的抗原有高度特异性。因此,利用单抗作为特异性载体制成导向药物(免疫偶联物),对于治疗肿瘤有巨大潜力和引人瞩目的前景。文章对烯二炔类抗肿瘤抗生素.特别对新制癌菌素、力达霉素和calicheamicins及其单克隆抗体免疫偶联物的研究进展作了概述。     

The selective cytotoxicity of cobra venom factor immunoconjugate on cultured human nasopharyngeal carcinoma cell line

The selective cytotoxicity of a CVF immunoconjugate on human nasopharyngeal carcinoma cell line was reported. Cobra venom factor (CVF), a C3b-like glycoprotein, was linked to BAC5, a murine monoclonal antibody directed against a human nasopharyngeal carcinoma-associated membrane antigen, by a disulfide bond. The high affinity to cultured human nasopharyngeal cells (CNE2) and the complement activating potency retained in CVF immunoconjugate. Although the equimolar concentration of BAC5 or CVF alone was harmless to CNE2 cells, the CVF immunoconjugate in the presence of fresh human serum exhibited selective cytotoxicity on CNE2 cells in a concentration- (IC50 3.07 x 10(-7) mol/L) and time-dependent manner. No cytotoxicity occurred on either CNE1 (another human nasopharyngeal carcinoma cell line) or MGC-803 (human gastric carcinoma cell line) cells. Furthermore, direct lytic factor (DLF, cardiotoxin) separated from cobra venom, augmented CVF immunoconjugate-induced cytotoxicity significantly. These results indicate that the CVF immunoconjugate has complement-mediated selective cytotoxicity on CNE2 cells, which can be potentiated by DLF.     

A novel antibody–drug conjugate anti-CD19(Fab)-LDM in the treatment of B-cell non-Hodgkin lymphoma xenografts with enhanced anticancer activity

Background: Rituximab is widely used in clinical setting for the treatment of B malignant lymphoma and has achieved remarkable success. However, in most patients, the disease ultimately relapses and become resistant to rituximab. To overcome the limitation, there is still a need to find novel strategy for improving therapeutic efficacy.

Objective: To construct genetically engineered antibody anti-CD19(Fab)-LDM, and verify the anticancer activity targeted toward B-lymphoma.

Methods: The anticancer activity of anti-CD19(Fab)-LDM in vitro and in vivo was examined. In vitro, the binding activity and internalization of anti-CD19(Fab)-LDP were measured. Using comet assay and apoptosis, the cytotoxicity of energized fusion proteins was observed. From in vivo experiments, targeting of therapeutic effect and anticancer efficacy bythe fusion protein was verified.

Results: Data showed that anti-CD19(Fab)-LDM does not only binding the cell surface but is also internalized into the cell. The energized fusion proteins anti-CD19(Fab)-LDM can induce DNA damage. Furthermore, significant in vivo therapeutic efficacy was observed.

Conclusion: The present study demonstrated that the genetically engineered antibody anti-CD19(Fab)-LDM exhibited enhanced cytotoxicity compared to LDM alone. One of the most powerful advantages of anti-CD19(Fab)-LDM, however, is that it can be internalized within the cells and carry out cytotoxic effects. Therefore, anti-CD19(Fab)-LDM may be as a useful targeted therapy for B-cell lymphoma.     

Preparation and characterization of a biodegradable drug targeting system for anticancer drug delivery: Microsphere-antibody conjugate

Targeted delivery of anticancer drugs is one of the most actively pursued goals in anticancer chemotherapy. A major disadvantage of anticancer drugs is their lack of selectivity for tumour tissue, which causes severe side effects and results in low cure rates. Any strategy by which a cytotoxic drug is targeted to the tumour, thus increasing the therapeutic index of the drug, is a way of improving cancer chemotherapy and minimizing systematic toxicity. This study covers the preparation of the gelatin microsphere (GM)-anti-bovine serum albumin (anti-BSA) conjugate for the development of a drug targeting approach for anticancer drug delivery. Microspheres of 5% (w/v) gelatin content were prepared by crosslinking with glutaraldehyde (GTA) at 0.05 and 0.50% (v/v) concentration. Microspheres were in the size range of 71–141 μm. The suitability of these microspheres as drug carriers for anticancer drug delivery was investigated in vitro by studying the release profiles of loaded methotrexate (MTX) and 5-fluorouracil (5-FU) and the cytotoxicities on cancer cell lines. The in vitro MTX release profiles (～22–46% released in 24 h depending on the amount of GTA used) were much slower compared to 5-FU (～42–91% released in 24 h). Both drugs demonstrated an initial fast release, which was followed by gradual, sustained drug release. The MTT cytotoxicity test results of GMs loaded with 5-FU and MTX showed ～54–70% and ～52–67% cytotoxicities in 4 days. In general, incorporation of MTX and 5-FU in microspheres enhanced the cytotoxic effect in a more prolonged manner compared to the free drugs. Gelatin micospheres were chemically conjugated to anti-BSA and the antigen–antibody activities were studied by immunofluorescence. Results indicated ～80% binding with conjugated anti-BSA and BSA-FITC. Based on their low cytotoxicity and the high antigen binding efficiencies, anti-BSA conjugated gelatin microspheres could be suitable targeted drug carrier systems for selective and long-term delivery of anticancer drugs to a specific body compartment (i.e. bladder cancer).     

Targeted delivery of monoclonal antibody conjugated docetaxel loaded PLGA nanoparticles into EGFR overexpressed lung tumour cells

The aim of this study was to develop anti-EGFR antibody conjugated poly(lactide-co-glycolide) nanoparticles (NPs) to target epidermal growth factor receptor, highly expressed on non-small cell lung cancer cells to improve cytotoxicity and site specificity. Cetuximab was conjugated to docetaxel (DTX) loaded PLGA NPs by known EDC/NHS chemistry and characterised for size, zeta potential, conjugation efficiency and the results were 128.4?±?3.6?nm, –31.0?±?0.8?mV, and 39.77?±?3.4%, respectively. In vitro release study demonstrated sustained release of drug from NPs with 25% release at pH 5.5 after 48?h. In vitro cytotoxicity studies demonstrated higher anti-proliferative activity of NPs than unconjugated NPs. Cell cycle analysis and apoptosis study were performed to evaluate extent of cell arrest at different phases and apoptotic potential for the formulations, respectively. In vivo efficacy study showed significant reduction in tumour growth and so antibody conjugated NPs present a promising active targeting carrier for tumour selective therapeutic treatment.     

Water-soluble polymers for targeted drug delivery to human squamous carcinoma of head and neck

Human squamous cell carcinoma of the head and neck (SCCHN) is characterized by over expression of a tumor cell surface-specific receptor namely Hsp47/CBP2 that makes it a favorable candidate for targeted delivery of anticancer drugs. Several synthetic peptides have been identified as effective ligands for binding to CBP2. The purpose of this study is to investigate the potential of water-soluble N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-doxorubicin (Dox) conjugates containing a Hsp47/CBP2 binding peptide sequence, namely WHYPWFQNWAMA for targeted delivery to SCCHN. An HPMA copolymer containing Dox and CBP2 targeting peptide conjugated via lysosomally degradable glycylphenylalanylleucylglycine (GFLG) spacer was synthesized by free radical precipitation copolymerization. A control polymer without targeting moiety was also synthesized. The conjugates were characterized for drug content, peptide content, molecular weight and molecular weight distribution. The uptake of polymeric conjugates by both drug resistant and drug sensitive SCCHN cells were determined in vitro by flow cytometry using FACS scan analysis. Cytotoxicity of the conjugates towards drug sensitive as well as multidrug resistant SCCHN cells were evaluated by a clonal survival assay and compared to free Dox. The cytotoxicity of the free peptide was similarly evaluated. The internalization and subcellular fate of the conjugates in drug sensitive SCCHN cells was monitored using confocal microscopy. The new targetable copolymer contained 0.16 mmole peptide/g polymer. Studies on drug sensitive SCCHN cells demonstrated lesser uptake of both targeted and non-targeted conjugates compared to free Dox suggesting a slower endocytic mechanism of uptake for the conjugates as opposed to rapid diffusion of free Dox. At higher Dox equivalent concentrations (>20 μM) the targeted conjugate showed significantly higher uptake (p≤0.028) than the non-targeted conjugate. The uptake of the targeted conjugate was inhibited in the presence of an anti Hsp47 antibody suggesting the involvement of active receptor mediated endocytosis in cell entry of the conjugate. Compared to free Dox, the targeted and non-targeted conjugates caused marginally lower inhibition (p≤0.01) of the drug sensitive SCCHN cells. In contrast, the same conjugates showed significantly higher uptake (p≤0.004) by drug resistant SCCHN cells and caused significantly higher inhibition (p≤0.02) of drug resistant SCCHN cells when compared to free Dox. Results suggest that the polymeric conjugates were able to overcome drug resistance. Confocal microscopy studies demonstrated the uptake of the polymeric conjugates, followed by internalization, intralysosomal localization and subsequent release of Dox. HPMA copolymer-Dox-peptide conjugates targeted to SCCHN cells were able to overcome drug resistance and increase efficacy in vitro. The results suggest that targetable polymeric conjugates have potential to improve systemic head and neck cancer chemotherapy by increasing tumor localization and reducing dose-limiting toxicity.     

Targeted Delivery of Doxorubicin by HPMA Copolymer-Hyaluronan Bioconjugates

Purpose. Overexpression of hyaluronan (HA) receptors on cancer cells results in enhanced endocytotic uptake of the drug conjugate. An N-(2-hydroxypropyl)methacrylamide (HPMA)-HA polymeric drug delivery system was used for targeted delivery of doxorubicin to cancer cells. Methods. HA-doxorubicin (DOX) bioconjugates (HA-DOX), and HPMA copolymer-DOX conjugates containing HA as a side chain (HPMA-HA-DOX) were synthesized. The cytotoxicity of the polymer-drug conjugate was evaluated via in vitro cell culture. The internalization of the conjugate was visualized by fluorescence microscopy. Results. Cytotoxicity of HPMA-HA-DOX targeted bioconjugate was higher against human breast cancer (HBL-100), ovarian cancer (SKOV-3), and colon cancer (HCT-116) cells when compared to the non-targeted HPMA-DOX conjugate. Fluorescence confocal microscopy revealed that the targeted HPMA-HA-DOX conjugates were internalized more efficiently by cancer cells relative to the non-targeted HPMA-DOX conjugate. Both HPMA-DOX and HPMA-HA-DOX showed minimal cytotoxicity toward mouse fibroblast NIH 3T3 cells. The internalization of polymer conjugates was correlated with their cytotoxicity. Conclusions. Selective delivery of anti-cancer agents to cancer cells was achieved by biochemical targeting. The HA-modified HPMA copolymer showed improved toxicity due to receptor-mediated uptake of the macromolecular drug.